Background: Prostate cancer (PC) is the second-most common cause of cancer.⁶⁸Ga-prostate-specific membrane antigen (PSMA)-11 positron-emission tomography/computed tomography (PET/CT) scan help in accurate staging of PC owing to its high PSMA avidity and specificity. The aim of this prospective observational study was to determine the incremental value of Ga-68 PSMA-11 PET/CT over multiparametric magnetic resonance imaging (mpMRI) in the locoregional staging of intermediate- and high-risk PC using histopathology from radical prostatectomy specimens as a gold standard. Materials and Methods: This was a prospective study, including 35 patients with biopsy-proven prostate carcinoma. All the patients underwent whole-body Ga-68 PSMA-11 PET/CT scans along with mpMRI including a dedicated pelvic imaging protocol within a time window of ± 10 days. The reference standard was based on histopathological results, postprostatectomy. Results: All 35 patients showed Ga-68 PSMA-11-avid disease, of which 29 underwent radical prostatectomy, one underwent radiation therapy, and five did not undergo surgery owing to metastases. A total of 52 PC lesions were detected in 29 patients on histopathology. Of 52 lesions, 29 lesions were identified in prostate parenchyma and 23 were extraprostatic lesions on histopathology. Ga-68 PSMA-11 PET/CT detected a total of 45 lesions, of which 29 lesions were located within the prostate parenchyma and 16 were representative of extraprostatic lesions. mpMRI detected a total of 36 lesions, of which 29 lesions were located within the prostate parenchyma and seven were representative of extraprostatic lesions. The overall sensitivity of⁶⁸Ga-PSMA PET/CT and mpMRI in the detection of lesions was 86.2% and 68.6%, respectively. However, the overall specificity was 94.7% and 89.1% for⁶⁸Ga-PSMA and mpMRI, respectively. Conclusion: Ga-68 PSMA-11 PET/CT provided superior locoregional preoperative staging of PC as compared to mpMRI in intermediate- and high-risk PC patients.

Objective: The aim of this study is to evaluate the prognostic significance of 18-fluorodeoxyglucose (¹⁸FDG) positron emission tomography/computed tomography (PET-CT) scan-derived total metabolic tumor volume (MTV) and total lesion glycolysis (TLG) in diffuse large B-cell lymphoma (DLBCL) patients with only nodal involvement. Methods: Twenty-five (age range: 22–82 years) biopsy-proven patients of DLBCL with only nodal involvement who underwent staging¹⁸FDG PET-CT scan were included in this study. Whole-body PET-CT performed at staging and PET-derived metabolic parameters, namely MTV and TLG of all FDG-avid lesions, were calculated for each patient. Total MTV was computed by summing the volumes of all FDG-avid lesions, the volume of each being calculated at threshold of 42% of the maximum standardized uptake value (SUV) using a semi-automatic software. TLG was calculated by summing the product of volume and SUVmean of each lesion. Patients were followed up to a period of 5 years and data obtained were divided into two groups, with recurrence and without recurrence. Results: Six patients developed recurrence on follow-up and 19 patients remained disease free on follow-up. The area under a curve (AUC) for MTV was 0.825 and for TLG was 0.623 suggesting MTV to be a good prognostic indicator and TLG poor indicator for predicting recurrence in these patients. In pairwise comparison of both the receiver operator characteristics, it was found that the difference between the AUCs of MTV and TLG was statistically significant (P = 0.0349). Thus, indicating MTV is a statistically better indicator than TLG. Conclusion: MTV is a better prognostic indicator than TLG in DLBCL patients.

Background: Response evaluation in locally advanced breast cancer is done through different methods ranging from clinical examination to magnetic resonance imaging, however evaluation with positron-emission tomography/computed tomography (PET/CT) in now being incorporated for the response evaluation. The aim of the present study is to correlate response to neoadjuvant chemotherapy (NACT) with PET/CT scan. Materials and Methods: The present study is a retrospective analysis of 30 locally advanced, triple-negative breast cancer patients. PET/CT scan was done pretreatment and post three and six cycles of NACT and was correlated with pathologic complete response (pCR). Responding disease was considered when there was at least a 50% reduction in the longest diameter. Results: The median pretreatment size of the breast lesion in CT scan was 3.9 ± 2.3 cm (2–12 cm) and maximum standardized uptake value (SUVmax) on PET/CT was 8.5 ± 5.5 (2.9–24). Among the responders, the median decrease in size of lesion was 3.2 ± 1.3 cm and median reduction in SUV of the tumor among was −8.1 ± 5.4 and was statistically significant when compared with nonresponders (P < 0.001). CT scan has 66% accuracy and PET has 82% accuracy at post three cycles NACT in predicting the pathological response. PET/CT had higher sensitivity and specificity when compared with CT findings alone in response evaluation. Conclusion: PET/CT scan can be considered as a sensitive tool for predicting pCRs and further larger trials are required to establish these findings.

Background: In diabetic (DM) patients, hyperglycemia degrades image quality in F-18 FDG PET CT by altering bio-distribution of FDG in the body and augmenting soft tissue and muscular uptake. We intend to evaluate the use of short acting I.V insulin in minimising the rescheduling of patients detected with FBG>160 mg/dL on the day of scan. Aim and Objectives: To show the utility of short acting IV insulin therapy in preparation of cancer patients incidentally detected with high blood glucose levels for F-18 FDG PET CT scan, (>160mg/dL) and to compare the obtained image quality with patients detected with fasting blood glucose level (FBG) <100mg/dL and <160 mg/dL, using visual and semi quantitative methods. Material and Methods: 613 cancer patients referred for PET CT were divided into 3 groups, Group I (n=30): known diabetics (DM) or incidentally diagnosed with FBG >160 mg/dL, Group II (n=349): DM patients with FBG <160 mg/dL (100-160mg/dL), Group III (n=234): Non DM patients FBG <100mg/dL. In Group I short acting insulin was given intravenously using a sliding scale, post insulin after 90 minutes F-18 FDG (radiotracer) injection was given and PETCT scan was obtained 60 mins post radiotracer injection. Qualitative image analysis was done using biodistribution score and quantitative analysis was done by chi square test, ANOVA (analysis of variance) and paired t-test. Results: In group I patients post insulin there was significant decrease in FBG levels (216±22.2 to 136±13.4mg/dL) and acceptable image quality. Comparison of quantitative parameters (mean and maximum SUV calculated by drawing ROI around brain, heart, liver, muscle, subcutaneous fat) among the 3 groups showed significant intergroup difference with p value <0.05. Conclusion: This short acting I.V insulin protocol is safe and can be used to obtain optimal quality F-18 FDG PET CT scan images by alleviating the need for rescheduling patients though they present with high glucose levels.

Purpose of the Study: Well-differentiated thyroid carcinomas have good prognosis, but as it de-differentiates, the survival rates go down. Early identification of such patients needs a marker which indicates the dedifferentiation process. CYFRA 21.1 has also shown to be increased in patients with¹³¹I refractory thyroid cancer. We tested whether CYFRA 21.1 can differentiate between¹³¹I avid and refractory tumors. Methodology: Well-differentiated thyroid cancer patients with known distant metastases were accrued and tested for stimulated and unstimulated thyroglobulin and CYFRA 21.1. All patients underwent¹³¹I whole-body scan,¹³¹I post therapy scan, and¹⁸F-Fluorodeoxyglucose positron emission tomography-computed tomography. Those with even a single¹³¹I nonavid lesion were considered¹³¹I refractory disease. CYFRA 21.1 of both¹³¹I avid and nonavid was compared, and CYFRA 21.1 levels against disease extent were analyzed. Results: CYFRA 21.1 levels were significantly elevated in¹³¹I refractory group. A cutoff value of 2.07 ng/ml distinguished between¹³¹I avid and refractory disease with high sensitivity and specificity (88% and 89. 7%, respectively). However, CYFRA 21.1 levels were similar in patients when analyzed based on disease sites. Conclusion: CYFRA 21.1 can be utilized to differentiate between¹³¹I avid and refractory diseases. Further long-term studies are required to use it as a predictive and prognostic marker.

Purpose: Graves' disease (GD) is the most common cause of hyperthyroidism. It was reported that the right thyroid lobe is generally larger, and it is more likely to be affected by thyroid disorders. The aim of the current study is to verify preferential affection of one of the thyroid lobes and incidence of higher activity of either thyroid lobe in patients with GD through analysis of quantitative data of Tc-99m thyroid scan and possible relation of different thyroid lobar activity to gender, age, and total thyroid uptake (TTU) level. Materials and Methods: Retrospective analysis of quantitative data of Tc-99m thyroid scan in patients with GD was done. Total and lobar thyroid uptake levels were analyzed and correlated with age, gender, and TTU. Results: GD was reported in 222 patients, representing 76.6% of those with hyperthyroidism, women represent 70.3% of patients. The right thyroid lobe uptake (RLU) figures were significantly higher compared to the left in the whole group as well as in women and in young patients (<40 years). This significance was lost in men and in old patients. Equal lobar uptake was found in 11 patients. 138 patients (62.2%) had higher RLU, while the remaining 73 patients (32.8%) had higher left thyroid lobe uptake, with statistically significant difference. This significant difference was found in women and in young patients and was absent in men and old patients. There is an increase in the incidence of patients with higher RLU in association with an increase in TTU. All women with TTU >30% had higher RLU figures. Conclusion: There is significant preferential thyroid lobar affection in favor of the right thyroid lobe in patients with GD, with significantly higher RLU figures and significantly more incidence of patients with higher right lobar activity. This significance is maintained in women and in young patients and lost in men and old patients. The incidence of higher right thyroid lobe activity also increases in association with increase in TTU. Our results emphasize the value of Tc99m thyroid scan in patients with GD, especially when surgery is the treatment of choice, helping to tailor suitable surgical procedure for each individual patient.

Background/Aims: Esophageal transit scintigraphy (ETS) is a useful tool for evaluating esophageal motility disorders, although conflicting results are seen due to lack of ideal bolus. Semisolid/solid boluses have shown superiority over liquid boluses, and the present study aims to establish the utility of in-house-prepared bolus in normal volunteers and its comparison with liquid bolus. Materials and Methods: Thirty-three healthy volunteers were selected for ETS with in-house-prepared semisolid bolus jelly containing^99mTc-sulfur colloid. Dynamic studies were acquired in anterior projection with single swallow for both supine and sitting positions. T90% esophageal emptying time (EET) was calculated for whole and three equally divided segments of esophagus and also done with liquid bolus on different day. Results: The median value of EET for semisolid bolus for whole esophagus in sitting and supine positions was 11.7 s (interquartile range [IQR]: 8.0–16.7) and 17.7 s (IQR: 12.0–33.0). EET of liquid bolus for whole esophagus in sitting and supine positions was 9.3 s (IQR: 8.0–13.3) and 13.0 s (IQR: 9.7–25.0), respectively. Significantly different EET for whole esophagus and lower one-third esophagus between sitting and supine positions was seen for semisolid (whole esophagus;P = 0.003, lower one-third esophagus; P = 0.025) and liquid boluses (whole esophagus; P = 0.032, lower one-third esophagus; P = 0.016). Comparing EET using semisolid and liquid boluses, only lower one-third esophagus in supine position showed significant difference (P = 0.033). Conclusions: In-house-prepared semisolid radiolabeled jelly is inexpensive, easy to prepare with good radiolabeling. Condensed dynamic images from semisolid bolus were better, sharper, and reproducible in comparison to liquid bolus without fragmentation. This study standardized semisolid bolus and verified its suitability for clinical use.

Background: Coronary artery calcification (CAC) can be visually estimated on computed tomography (CT) attenuation correction (CTAC) of positron emission tomography (PET). The visual estimation of CAC from CTAC scans performed for PET/CT is comparable to the standard CAC score scan. Myocardial perfusion imaging (MPI) with single-photon emission CT (SPECT) is commonly performed for risk stratification before oncologic surgery. Objective: We investigated the value of visual estimation of CAC from CTAC of PET/CT as well as other factors such as coronary artery disease (CAD) risk factors and type of cancer as predictors of MPI ischemia. Methods: Retrospectively, we identified 268 patients who underwent PET/CT and MPI for preoperative cardiac evaluation. Visual estimation of CAC was performed and classified into four categories. Results: The results of visual CAC were as follows: 47.8% – zero CAC, 32.8% – mild CAC, 14.2% – moderate CAC, and 5.2% – severe CAC. The majority of patients (85.8%) had normal MPI, whereas 14.2% were abnormal. There was a strong association between ischemia on MPI and CAC seen on CTAC (P < 0.01), dyslipidemia (P < 0.01), family history of CAD (P < 0.05), smoking (P < 0.01), and type of malignancy (P < 0.01). Conclusion: A strong association exists between visual estimation of CAC on CTAC and MPI. Zero is highly associated with normal MPI, but moderate-to-severe CAC is associated with abnormal MPI, in addition smoking, dyslipidemia, and certain cancer are associated with ischemic MPI; subsequently, preoperative cardiac testing is warranted in these subsets of patients.

Objective: The objective of this study is to assess the efficacy of Yttrium-90 (Y-90) radiation synovectomy in decreasing the recurrent bleeding episodes in hemophilic joints. Subjects and Methods: A retrospective analysis of patients who had Y-90 synovectomy from January 2001 to January 2016 was done. Among them, patients with minimum follow-up of 6 months were selected. The response in terms of decrease in the number of bleeding episodes was evaluated. Results: A total of 167 patients (243 joints) with hemophilia had radiation synovectomy over 15 years. Those with a minimum follow-up of 6 months were 155 joints (115 patients). The age ranged from 5 to 43 years and included 113 male and two female patients. Data for 11 joints were unavailable as these patients were lost to follow-up. The assessment of response for the remaining 144 joints was done based on the data available for different follow-up periods. They were divided into the following – 7 months to 2 years (89 joints), 3–5 years (6 joints), 6–10 years (39 joints), and above 11 years (10 joints). Overall, 37.4% of the joints had complete response, 56% had partial response, and 6% of the joints had no response. Conclusion: Radiation synovectomy is a noninvasive and effective modality which decreases the bleeding episodes in hemophiliac joints and improves the quality of life remarkably.

Myocardial perfusion single-photon emission computed tomography (SPECT) as a common imaging procedure in nuclear medicine laboratories may encompass findings in the heart or beyond it, in the thorax or abdomen, which may be related or unrelated to the symptoms of the patients. Sometimes, these findings may be discovered incidentally. In the present article, it is aimed to present some less frequent cardiac and extracardiac findings including radiolabeled emboli, transposition of great arteries, breast prosthesis, breast tissue uptake, pericardial effusion, hiatal hernia, hepatocellular carcinoma, ascites, aortic aneurysm, splenomegaly, and polycystic kidney disease during^99mTc-methoxyisobutylisonitrile myocardial perfusion SPECT with their radiological correlates.

Gated imaging, as a technically demanding procedure, requires special attention and effort to fulfill the technical adequacy and accuracy of the study, based on the available standard guidelines. One of the essential requirements to be met by both technologists and physicians, in nuclear cardiology, is triggering and synchronization as a fundamental subject of gating. There are many sources of gating errors that produce imaging artifacts and, in some occasions, render the images uninterpretable or the quantitative analyses less accurate. Sufficient knowledge of recognition of these artifacts and understanding of their related mechanisms (from physical and technical perspectives) enable the technologists and physicians to promote their performance in daily practice. In this article, intended as a readily practical technical review for nuclear medicine practitioners, it is aimed to present the technical and computer aspects of triggering and synchronization as well as the related errors during imaging.

Melanomas are usually cutaneous in origin but rarely can also arise from the mucosal linings in the body. Sinonasal melanomas arise from the mucosa of the nasal cavity and paranasal sinuses, which account for approximately 50% of mucosal melanomas in the body. 18F fluorodeoxyglucose positron emission tomography-computed tomography (¹⁸F-FDG PET/CT) has proven its role in malignant melanoma in staging especially in stage III and IV disease, restaging, assessing response to therapy and had affected in treatment change in significant number of cases. We present a case of sinonasal melanoma who underwent FDG PET/CT for staging and showed cervical lymph node and marrow metastases.

Extraskeletal tracer uptake in methylene diphosphonate (MDP) bone scan is not a common finding. There have been several case reports in the literature showing diffuse splenic uptake in MDP bone scan. We present a case of sickle cell disease, which showed diffuse splenic uptake on MDP whole-body bone scan.

We present fluorodeoxyglucose positron emission tomography–computed tomography (FDG PET-CT) findings in an extremely rare case of penile metastasis from renal cell carcinoma. A 66-year-old male, a known case of renal cell carcinoma, underwent FDG PET-CT. The scan showed metabolically active cervical lymph nodes, lytic skeletal lesions, deposit in the left adrenal gland, and nodules in the bilateral lungs, indicating metastatic disease. In addition, a hypermetabolic lesion was seen in the corpus cavernosum of the shaft of the penis, suggestive of penile metastasis. Follow-up PET-CT after tyrosine kinase inhibitor therapy showed reduction in size and metabolic activity of all previously seen lesions including penile lesion, suggestive of favorable response to therapy.

Lymphomatoid granulomatosis (LYG) is a rare, extranodal B-cell lymphoproliferative disorder. The disease commonly presents with nonspecific symptoms and imaging features, making the diagnosis and therapeutic response assessment difficult. While histopathology is the mainstay of diagnosis, different imaging modalities such as computed tomography (CT), magnetic resonance imaging, or F18-fluorodeoxyglucose positron emission tomography/computed tomography (F-18 FDG PET/CT) can help in identifying the different organs involved. We present a case of LYG, post chemotherapy in remission for the past 5 years, presenting with symptoms of disease recurrence.

Inflammatory myofibroblastic tumor (IMT) or inflammatory pseudotumors are a rare group of tumors usually affecting children and young adults. They occur in various anatomic locations, with most common being the lung accounting for almost 95% of the cases. We present a case of a 4-year-old girl who presented with fever and dull abdominal pain for 6 months with a clinically palpable left hypochondrium mass. On suspicion of mesenteric/gastric neuroendocrine tumor,⁶⁸Ga-DOTA-NOC positron-emission tomography-computed tomography was done; however, the biopsy revealed IMT.

Inguinal hernia is a common pathology seen in the general population. However, the presence of herniated urinary bladder in the inguinal canal is a rare condition. Most cases are asymptomatic and are detected incidentally either during surgery or on imaging. Here, we present a report, where a patient, diagnosed case of carcinoma esophagus, was referred for staging¹⁸F-fluorodeoxyglucose positron-emission tomography/computed tomography (FDG PET/CT) scan and revealed FDG uptake in the right inguinal canal, other than primary and metastatic lesions and corresponding CT and fused PET/CT images revealed herniated urinary bladder in the inguinal canal.

Multiple primary malignancies in a single patient are exceedingly rare, but their prevalence has increased in recent decades due to prolonged survival rates supported by the advent of newer and better generation of chemotherapeutic agents as well as advances in cancer detectability facilitated by sophisticated modalities such as positron emission tomography-computed tomography. Here, we discuss a case of a 66-year-old male who recovered completely from lung carcinoma but subsequently developed synchronous gall bladder and gastric carcinoma after 1 year.

Somatostatin (SST) cell surface receptors (SSTRs) are expressed in many different malignant, benign, and neuroendocrine tumors. SSTRs are also expressed in the endothelium of human vessels during angiogenesis and not in the nonproliferating vessels. We present a case of 19-year-old boy with juvenile nasal angiofibroma (JNA), who underwent⁶⁸Ga-DOTANOC PET/CT to explore SSTRs expression and theranostic potential. The scan revealed high uptake in the tumor, and in certain areas, the uptake was similar to that of the pituitary gland. Performance of DOTANOC PET/CT in JNA opens up new frontiers with respect to radiological staging, early recurrence identification, better delineation from postoperative scar tissue, possible preoperative treatment with SST analogs, and perhaps even radiopharmaceutical based-ligand therapy of inoperable/residual/recurrent JNAs in the future.

Isolated mandibular metastasis is very rare from carcinoma urinary bladder with no locoregional lymph node involvement. Here, we present a case where staging fluorodeoxyglucose - positron emission tomography - computed tomography (FDG PET-CT) scan showed an FDG avid primary lesion in carcinoma urinary bladder with FDG avid erosion in the right mandibular condyle. However, since no pelvic lymph nodes were involved, the mandibular lesion was kept on follow-up and cystoprostatectomy was performed. Follow-up FDG PET-CT scan after 6 months revealed an osteolytic destructive lesion in the mandible with associated soft tissue component and the biopsy confirmed this as metastatic lesion.

Many surgical procedures may injure lymphatic channels unexpectedly, such as lymph node dissections, transplantations, and vessel reconstructions, and will lead to iatrogenic lymphatic leakage. We hereby present a case of postoperative lymphocele diagnosed more precisely by single-photon emission computed tomography (SPECT)/CT fusion imaging.

Thymomas are rare anterior mediastinal tumors that originate in the epithelial cells of the thymus and have a rare propensity to metastasize to extrathoracic locations unless it is a histologic high-grade neoplasm (type B and above). We describe a case of 50-year-old woman diagnosed with type AB thymoma and the role of¹⁸F-fluorodeoxyglucose positron emission tomography–computed tomography in accurate delineation of extrathoracic metastases during initial staging.